Upgrading fire control systems

Abstract

A conversion kit for upgrading an existing fire control radar system having a target radar antenna for tracking a target to enable the system also to track, with respect to the target, a missile having a beacon transmitter. The conversion kit includes a missile antenna for measuring and commanding the missile, a mechanism for attaching the missile antenna to the target radar antenna of the fire control radar system, a command transmitter for transmitting command signals via the missile antenna to a missile, a beacon receiver for receiving from the missile, via the missile antenna, response signals from the missile beacon transmitter in response to the reception by the missile of the command signals, and a guidance computer for utilizing the command signals transmitted by command transmitter, and the response signals received from the missile beacon transmitter, and target tracking signals received from the fire control radar system, for tracking the missile and for guiding it to the target.

What is claimed is: 
     
       1. A conversion kit for upgrading an existing fire control radar system having a target radar antenna for tracking a target to enable the system also to track, with respect to the target, a missile having a beacon transmitter, said conversion kit comprising: missile antenna means for measuring and commanding the missile;   means for attaching the missile antenna means to the target radar antenna of the fire control radar system;   a command transmitter for transmitting command signals via said missile antenna means to a missile;   a beacon receiver for receiving from the missile, via said missile antenna means, response signals from the missile beacon transmitter in response to the reception by the missile of said command signals;   and a guidance computer for utilizing said command signals transmitted by said command transmitter, and said response signals received from the missile beacon transmitter, and target tracking signals received from the fire control radar system, for tracking the missile and for guiding the missile to the target.   
     
     
       2. The conversion kit according to claim 1, wherein said kit further includes means for generating a synthetic target at a predetermined known location with respect to said missile antenna, and means to enable self-calibration of the conversion kit with respect to the target radar antenna for different frequencies of the target antennas and of the kit antennas. 
     
     
       3. The conversion kit according to claim 2, wherein said means for generating a synthetic target comprises: a repeater at said predetermined known location for transmitting a signal corresponding to an echo received by the fire control radar when tracking a target;   a beacon transmitter at said known predetermined location for transmitting a beacon signal corresponding to the signal transmitted by the missile to be tracked;   synthetic target antenna means at said predetermined known location, including a missile antenna and a target antenna having an accurately known electromagnetic center;   and a controller including means for operating said repeater and said beacon transmitter;   said guidance computer further including means for computing and recording from the signals received by said target radar antenna of the radar system, and said missile antenna means of the conversion kit, the errors in azimuth and elevation when said repeater and beacon transmitter are triggered at said different frequencies over their respective frequency band and over the bandwidth of the guidance antenna.   
     
     
       4. The conversion kit according to claim 1, wherein said missile antenna means comprises a monopulse capture antenna for measuring and commanding the missile within a relatively wide capture beam; and a monopulse guidance antenna for measuring and commanding the missile within a relatively narrow guidance beam. 
     
     
       5. The conversion kit according to claim 4, wherein the beam width of said monopulse capture antenna is 10-18°. 
     
     
       6. The conversion kit according to claim 4, wherein the beam width of said monopulse guidance antenna is 1-2°. 
     
     
       7. The conversion kit according to claim 1, further including means for measuring the physical distortion of the target radar antenna because of variations in temperature, said guidance computer including means for correcting the measurements of the missile and the guidance thereof to the target to compensate for said physical distortion. 
     
     
       8. The conversion kit according to claim 7, wherein said means for measuring the physical distortion of the target radar antenna comprises: a point-source light emitter adapted to be located at a predetermined known location with respect to said target radar antenna;   a light detector adapted to be located at a predetermined known location with respect to said target radar antenna;   a first mirror located on said target radar antenna for receiving light from said point-source light emitter;   a second mirror located on said target radar antenna at a known predetermined location with respect to said first mirror and oriented to receive the light reflected from said first mirror, and to reflect said light to said light detector;   and means for measuring the physical distortion of said target radar antenna for the differences in the actual point of impingement of the light on said light detector as compared to the theoretical point of impingement thereon in the absence of any physical distortion of the antenna.